[Tizen][Runtime] Enable "allow-navigation" feature for Tizen legacy WGT package.

In Tizen WGT package configure document, the <tizen:allow-nevigation>
tag will list all allowed domains of navigation links can be displayed
in web application.

Please refer to the section "0260 Tizen Navigation Policy"
https://source.tizen.org/sites/default/files/page/tizen-2.2-wrt-core-spec.pdf
for more details.
[Tizen][Runtime] Add tizen application handler.

Add a handler for tizen application element, so that we
can get and validate tizen application info from tizen
particularly widget package.

Feature=https://crosswalk-project.org/jira/browse/XWALK-1161
FeatureID: 0200, 0210
[Runtime] Fix using uninitialized variable "is_valid_" for WGT package
extracting.

The uninitialized variable "is_valid_" in package.cc(h) may lead to
error when installing a WGT package, and it should be initialized before
using it in Extract method.
Merge pull request #1777 from yeyuyinjie/master

[Tizen][Runtime] Add tizen application handler.
Merge pull request #1756 from takethathe/fix_package_extract

[Runtime] Fix using uninitialized variable "is_valid_" for WGT package extracting.
Merge pull request #1768 from takethathe/navigation_link

[Tizen][Runtime] Enable "allow-navigation" feature for Tizen legacy WGT package.